Lenovo A536 User manual

1

Lenovo A536

Service Manual

LENOVO

2

Content

1. How to assemble and disassemble LENOVO A536 ................................................................. 3

1.1 The phone disassemble guide ........................................................................................ 3

1.2 The phone assemble guide ............................................................................................ 9

2. Main board and Sub FPC layout introduction ......................................................................... 10

2.1 Main board top view ...................................................................................................... 10

2.2 Main board bottom view ............................................................................................... 11

3. Troubleshooting Procedure ..................................................................................................... 12

3.1 No boot ......................................................................................................................... 12

3.2 Touch panel have no effect ........................................................................................... 13

3.3 Charging anomaly ......................................................................................................... 14

3.4 Calling receiver sound has poor quality ....................................................................... 16

3.5 Speaker has no sound .................................................................................................. 17

3.6 LCD has no display ....................................................................................................... 18

3.7 Phone crash .................................................................................................................. 20

3.8 Key has no effect .......................................................................................................... 21

3.9 Communication signal abnormality .............................................................................. 22

3.10 Calling receiver has no sound ...................................................................................... 23

3.11 Microphone has no effect ............................................................................................. 24

3.12 Display color distortion.................................................................................................. 25

3.13 Speaker tone distortion ................................................................................................. 26

3.14 Speaker tone smaller .................................................................................................... 27

3.15 No charging................................................................................................................... 28

3.16 Camera has no effect ................................................................................................... 29

3.17 Auto shutdown .............................................................................................................. 31

3.18 SIM Card has not be detected ...................................................................................... 32

3

1. How to assemble and disassemble

LENOVO A536

1.1 The phone disassemble guide

1) Remove battery cover

Remove battery cover from B cover at the buckle, shown as picture (1) and (2).

(1)

(2)

2) Remove screws

Remove the 7 screws as shown below. Use cross head driver to remove the screws.

Battery cover

Buckle

4

Screw length to 1 & 2 & 3 & 4 positions are S1.6×L4.1×D2.6×T0.5

Screw length to 4 & 5 & 6 positions are M1.4X2.8

3) Remove B cover

Separate B cover from A cover at the buckle, then unclench B cover and A cover with a

plectrum alongside the shell gap.

1

2

5

6

7

3

4

Buckle

B cover

5

4) Disassemble PCBA

Open the FPC connector of TP, LCD and Camera, and extract all the FPCs.

TP FPC is glued to the main board

Pull off side key FPC from A cover, and remove it from main board with a soldering iron.

Side key FPC is glued to the A cover.

Remove the foam on the main board.

Side key FPC

LCD FPC

TP FPC

Camera FPC

6

Remove the vibrator wire from the main board with a soldering iron.

Remove the speaker from A cover. The speaker is glued on the A cover, need to pry up

with tweezers.

The speaker adhesive comes along with the speaker.

Remove the main board from A cover.

Foam

Vibrator wire

Speaker

7

5) Remove front camera and MIC rubber

Open the front camera FPC connector and extract the FPC.

The camera adhesive comes along with the front camera.

Remove the front camera foam.

Remove two MIC rubbers on the main board. Positions of MIC rubbers are shown below.

Front camera

8

6) Remove speaker

Remove speaker from the main board with a soldering iron.

7) Remove main camera, receiver and vibrator from A cover.

Main camera, receiver and vibrator are glued to the A cover.

The adhesives come along with main camera, receiver and vibrator.

MIC rubber

Speaker

Main camera

Receiver

Vibrator

9

1.2 The phone assemble guide

Assemble and disassemble process is opposite

10

2. Main board and Sub FPC layout

introduction

2.1 Main board top view

11

2.2 Main board bottom view

12

3. Troubleshooting Procedure

3.1 No boot

Cannot boot

Y

Power on the alone PCBA, which be provided

power by power monitor. Whether the power

monitor current is larger than normal?

Y

PCBA is bad,

change it.

N

Y

Check the battery connector

SMT is normal?

Heat the battery connector

then try it again.

Check whether the power

button FPC assembly is good?

Change the power key FPC?

Y

If change the power key FPC,

then the phone can power on,

the root cause is FPC.

Connect the phone to the computer through

the USB line, check the computer device

manager if there is equipment pops up.

Y

Download software and

try power on it again.

N

Check PMIC provide power supply

to CPU and EMMC are normal?

N

Heat the PMIC or

change the PMIC.

Y

Change memory chip U501

13

3.2 Touch panel have no effect

Touch panel have no effect

Touch panel

is not normal?

Touch panel is not

good, change it.

The SMT of touch panel connector

and EMI filter is not normal?

Y

N

Heat the touch panel

connector and EMI

filter.

Change CPU chip

Using the oscilloscope, the I2C

controller line has signal output?

N

Y

14

3.3 Charging anomaly

3.3.1 The charger is plugged in, without charging display

Replace the charger

The charger is plugged in,

without charging display

N

Y

Whether the charging is normal after

replace the battery? Measure the battery

voltage, whether it is less than 3V?

Replace the battery

Y

N

Checks the SMT quality of these

components include the PMU, USB

connecter, and the peripheral parts.

Whether these parts are SMT good?

The phone is work good after heating

these parts?

Y

OK

N

Whether the charging is normal after

replace the charger or USB line?

Y

Replace the PMIC

OK

15

3.3.2 Connect the phone and computer through USB line,

but not any new device was found in the computer

N

Y

Connecting the phone and

computer through USB

line, but not any new device

was found in the computer.

Whether the charging is normal after

replace the charger or USB line?

Replace the charger

Whether the charging is normal after

replace the battery? Measure the battery

voltage, whether it is less than 3V?

Replace the battery

Checks the SMT quality of these

components include the PMU, USB

connecter, and the peripheral parts.

Whether these parts are SMT good?

The phone is work good after heating

these parts?

Y

OK

N

Replace the PMIC

N

Y

OK

16

3.4 Calling receiver sound has poor quality

Calling receiver sound

has poor quality

N

Y

OK

N

Replace the codec IC

Checks the SMT quality of bead.

Whether these parts are SMT

good? The phone is work good

after heating these parts?

Measure the resistance of

receiver, is the value

32ohm?

Check whether the contact is good

between receiver spring and contact

point. Re assemble the receiver and

whether the phone work is good.

Y

OK

Replace the

receiver.

N

Y

17

3.5 Speaker has no sound

Replace the codec IC

U201

Checks the SMT quality of

these components include the

BEAD on the Sub board

Whether these parts are SMT

good? The phone is work good

after heating these parts?

N

Replace the speaker, and then

does the phone work normal?

Whether the speaker spring is

normal?

Y

OK

Speaker has no sound

N

OK

Y

Replace the Sub FPC, and then

does the phone work normal?

Y

Replace the

Sub FPC.

N

18

3.6 LCD has no display

3.6.1 Power on and no display

White or black screen and

have no display, backlight

is good.

Checks the SMT quality of these EMI

filter. Whether these parts are SMT good?

Whether the powers supply are normal?

OK

Checks the SMT quality of LCD

connector. Whether these parts

are SMT good?

The SMT of LCD connector

and EMI filter is not normal?

N

Y

OK

Y

Replace the LCD，whether

the screen display is normal?

N

OK

Y

Heat these

parts.

N

Replace the CPU（U201）

19

3.6.2 LCD has no display

Check whether the LCD

backlight driver output

voltage is exceeding 20V.

OK

The backlight circuit

is normal, and the

LCD module is bad.

Checks the SMT quality of

LCD backlight driver IC.

Whether these parts are

SMT good?

Y

N

Y

Check whether the connection

status between the LCD

module FPC connector and the

motherboard connector is

normal, and reconnect the

connector whether the phone is

working normal.

N

LCD has no

backlight

Replace the LCD module,

and make sure whether the

LCD has the backlight.

OK

Y

N

OK

20

3.7 Phone crash

Check PMIC provide power

supply to CPU and EMMC

are normal?

Y

Heat the PMIC

or change the

PMIC.

Connecting the phone and

computer through USB line,

check whether some new device

was found in the computer.

N

Phone crash

N

Download software

Heat the crystal

then try it again.

Check the 32.768KHz crystal

is normal?

N

Replace the memory U501,

whether the phone is

working normal.

OK

Y

N

Change CPU chip

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Lenovo A536 User manual

Lenovo A536 User manual

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